The correct answer is B. Hindi.
Hindi is the official language of Jharkhand. It is the most widely spoken language in the state, with over 80% of the population speaking it as their first language. Hindi is also the language of administration and education in Jharkhand.
Sadri is a dialect of Hindi that is spoken in the eastern part of Jharkhand. It is the mother tongue of about 10% of the population of the state. Sadri is not an official language of Jharkhand, but it is used in some government offices and schools.
English is a second official language of Jharkhand. It is used in government offices, schools, and universities. English is also the language of business and commerce in Jharkhand.
Urdu is not an official language of Jharkhand. It is spoken by a small minority of the population of the state. Urdu is used in some mosques and madrasas.